Elastic wheel



April 29 1924. v. M. CABRETO$A ELASTIC WHEEL Filed Dec. 4. 1922 2Sheets-Sheet 1 April 29, 1924.

V. M. CABRETOSA ELASTIC WHEEL Filed Dec. 4, 1922 2 Sheets-Sheet 2Patented Apr. 29, 1924.

eases earner series.

VALENTIN MABTI GABRETOSA, OF- BARCELONA, SPAIN.

ELASTIC WHEEL.

Application filed December 4, 1922. Serial No. 604,881.

To all whom it may concern:

Be it known that I, VALENTIN MARTI CABRETosA, subject of the King ofSpain, residing at Barcelona, Spain, have invented certain new anduseful Improvements in Elastic Wheels, of which the following is aspecification.

This invention relates to elastic wheels the spokes of which areconstituted by springs formed of curved laminas. In this kind of wheels,arrangements are already known of springs in two groups, the springs ofone group being located in planes passing through theaxis of the wheel,while the springs of the other group are located in planes transverse tothe axis of the wheel.

According to this invention the springs located in planes transverse tothe axle are arranged in pairs, the two springs of each pair beingopposite one another at the two sides of the wheel and converging fromthe hub to the rim. The springs are made of curved elastic strap andeach of the springs has two branches, which extend forming difierentcurves and with more pronounced curvature towards one end of the springthan towards the other. These double springs are arranged in such .amanner that the springs, located in axial planes of the wheel, have thecurvature of their branches of lesser radius nearer the hub than therim, and the springs of the other group their curvature of lesser radiusnearer the rim. This positions the sharper curves of p the springs whichare in the axial planes, nearer the hub, and the sharper curves of thesprings of the other group, nearer the rim. By this means the mostcomplete utility of the available space is obtained, for the purpose ofplacing springs therein. Further, the very important advantage isobtained that the springs of the groups of springs which are alternatelyparallel with, and transverse to, the axle of the wheel, will, when thewheel is submitted to an excessively strong force, contact at. theirbroad curves, which generally have a free space between them, and theywill then be in such contact with each other, that thewheel is madealmost rigid, and the risk of breakage is avoided.

In order to prevent ruptures, the special arrangement of the union ofthe springs with the hub and rim and of the two branches of each springwith each other is of great importance. According to this the bedding ofthe springs. .19 the two branches of the metallic strap invention, thisunion is efiectuated by means of special washers that maintain thepartsof the respective springs at a determinate distance from each other, andfrom the p0rtion of the wheel to which they are jointed. As a furtheradvantage in regard to the form and special disposition of the doublesprings, it should be kept in mind that these springs have exactly thesame shape for both groups, whereby their construction and upkeep isgreatly facilitated and cheapened.

The exterior surfaceofthe hub is formed to serve as a support for thetransverse and longitudinal springs. In a like manner the interior faceof the rim is formed to receive the terminal flanges of the transversesprings and the central bedding of the longitudinal springs.

In the annexed drawing an example of a preferred construction. of acarriage-wheel is shown in accordance with the invention.

Fig. 1 is an elevation of a sector of the wheel, and

Fig. 2 is a vertical section on line II of Fig. 1.

The wheel is applied to the collar or mutt 1- which at its outer partcarries the cover 3-screwed thereon, while the inner end is furnishedwith an annular or ringshaped prolongation 2 in the shape of a flange.The hub 567-8-- which forms the bedding of the springs, rests with itsfrontwall 7- and the rib 6' on cover 3-, and by means of the other wall--5--, on the flange of the prolongation --2 of collar 1-. For the sakeof accurate fit and adjustment, the walls 6- and -5 terminate in conicalsurfaces are curved symmetrically towards each other forming the curve-l2- with the subsequent throat --13. Then the two branches separateforming part -14t of large invteriur radius, and immediately after theyapproacheacli other again, being curved or undulated in -15, andforming, finanythe sinus ---16 of reduced dimension. From part -16- thetwo branches continue parallel to" each other, forming. part -l 7-- andthe ends .l8 are bent forming flanges for fixing the spring. At the part1 7- the two branches of eachspringare jomed to getherbyfthe rivet 20-,with' an. inter-.

posed washer ----2l-- which'serves to isolate the branches from contactwith each other.

Eachspring, is fixed to the hub, and the-rim by means of screws -.-22-with interposed washers -23. 7

While Ilconsider it preferable to make eachspring of one single strapbent in order to form the two branches of the spring,

. it is also possible to make the two branches of the springindependently and afterwards join them together by rivets or otherwise.I

As can be. seen in Figs. 1 and 2, a transverse spring --31- is combinedalternately with two longitudinal springs -30-- at each side, thetransverse springs 31 extending with their shafts in the manner of th6usual wheel-spokes, whereas the longitudinal springs 30- are inclinedand converge relative to each other towards the rim. At the same time,the longitudinal springs 30-- have a reversed position relative to,

30, in order that, in the case of an abnormal flattening of the wheel,the springs will rest on one another by the body contact of their largerbared portions 14 and constitute a rigid whole.

The rim has the inclined surfaces 2-land 25- the slant of which is suchas to enable the, bases of the longitudinal springs '30 to rest on them,leaving the rim in an outwardly inclined position (Fig. 2). A result ofconstructing the elastic wheel in accordance with the drawing andspecification, is, that all the forces which the wheel receives, aretransmitted to the springs' 3'0-- and -31iwhich withstand not onlyradial "forces, but also transverse forces, the latter bein' compensatedby the arrangement and inclination of the longitudinal springs 3l)--.The shape and 'rangement of the springs represented in the drawing,produce exceedingly resisten wheels of'very great elasticity.

J. claim: 1. An elastic wheel having, in combination, a hub, a rim, aseries of two branch springs made of elastic curved members and locatedinplanes passing through the axis of the wheehand a series of similarsprings arranged opposite one another in pairs, and located in planestransverse to the'axis or" the wheel, the springs of each pairconverging relative to each other from the hub to the rim, the branchesof all of said springs being formed. in several unequal curves, the,largest of which is nearer the hub in the springs placed in axialplanes, and nearer the rim in the springs placed in the transverseplanes.

2. An elastic wheel comprising a hub, a rim, spokes uniting the hub withthe rim and each formed of spring of two branches forming an open endedloop, and made of elastic curved blades formed in several unequalcurves, some of said spokes being situated in axial planes of the wheeland fixed at the closed. ends of their vloops to the hub of the wheel,and at the open ends of their. loops to the rim, the remainder of thespokes being arranged in pairs, and situated in planes transverse to theaxis'of the wheel, the

spokes of each pair converging relative to each other from thehubtowards the rim and each member of a pair being fixed at the closedendof its loop, to the hub, the

pairs of spokes and the axial spokes be- 7 ing positioned alternatelyaround the wheel.

An elastic wheel comprising a hub, a rim, spokes uniting the hub to therim, each spoke being formed of an elastic curved blade having two"symmetrical branches forming several unequal curves, said spokes beingfixed to, the hub and to the rim, and being divided into two groups, thespokes of one group being situated in axial planes of the wheel, and thespokes of the other group being arranged in pairs, and situated inplanes transverse to the axis of the wheel, the spokes of each pairconverging relative to each other from the hub towards the rim. 7

4. An elastic wheelcomprising a hub, a rim, and a plurality of loopedspokes connecting the hub and the rim, some of the spokes beingpositioned with the plane or" their loop in axial planes of the wheel,and the remaining spokes, being arranged in opposing pairs, andpositioned with the planes of their loops in planes substantiallytransverse to the axis of the wheel.

5, A wheel according to claim 4, the spokes that are arranged in pairs,converging'relative to each other toward-the rim,

In testimony whereo fl have signed. my

name to this specification. H I .VALENTIN MARTI OAB-REIO'SA.

